WO2008050547A1 - Substrate for display device and method for producing the same - Google Patents

Abstract

Disclosed is a substrate for display devices which is excellent in gas barrier properties, flexibility, heat resistance, dimensional stability, handleability and secondary workability. Specifically disclosed is a substrate for display devices which comprises an inorganic glass, and a resin layer arranged on both sides of the inorganic glass. Preferably, the ratio of the total thickness drsum of the resin layers and the thickness dg of the inorganic glass, namely drsum/dg is 0.5-2.2. More preferably, the resin layers on both sides of the inorganic glass are composed of the same material and have the same thickness which is equal to the thickness of the inorganic glass. The average linear expansion coefficient of the substrate for display devices at 170˚C is preferably not more than 20 ppm˚C-1.

Description

 Specification

 Display element substrate and manufacturing method thereof

 Technical field

 The present invention relates to a display element substrate and a method for manufacturing the same. More specifically, the present invention relates to a display element substrate excellent in gas barrier properties, flexibility, heat resistance and transparency, and excellent in dimensional stability, operability and secondary processability, and a simple manufacturing method thereof. . Background art

 [0002] In recent years, with the development of video communication technology, liquid crystal display elements have become larger for stationary types and lighter and thinner for portable terminals. In the future, in addition to making the board thinner and lighter, it will be necessary to make it flexible in order to realize curved display of large panels that require a high level of realism and roll-up portable terminals that pursue portability and convenience.

 Conventionally, glass substrates are often used as substrates for liquid crystal display elements. The glass substrate has high heat resistance enough to withstand photo-etching processes such as alignment film formation process and electrode formation process in the manufacturing process of liquid crystal display elements that only have excellent transparency, solvent resistance and gas barrier properties. Have. However, if the thickness of the glass material constituting the glass substrate is reduced so as to be bendable, the impact resistance becomes insufficient and the handling becomes difficult.

 [0004] In view of this, technological development is progressing in which a resin film or a resin sheet, which has excellent impact resistance and is lighter and more flexible than glass, is used as a base material of a display substrate. However, since conventional resin substrates for display elements have lower heat resistance than inorganic materials such as glass, electrodes are especially used in thin film transistor (TFT) substrates that require high temperature processing. It has been pointed out that cracks occur, resulting in increased resistance and disconnection.

[0005] In order to improve heat resistance, if an aromatic ring or hetero ring is introduced into the main chain and a resin having a highly conjugated structure is used, the substrate is inevitably colored, and sufficient display performance is obtained. Absent. Polycarbonate, polyarylate, polyethersulfone, etc. are being studied as resin substrates with transparency and heat resistance. Such resin substrates still have thermal expansion. Tensile property (linear expansion coefficient: dimensional stability) is insufficient (specifically, the linear expansion coefficient of the resin substrate is about δθρρπ ^ θ ¹ and about 10 times that of non-alkali glass for display). In addition, when a resin substrate is used, it is necessary to form a gas barrier layer on the surface, which causes problems such as a decrease in yield and an increase in cost due to an increase in manufacturing steps.

[0006] On the other hand, a laminate substrate having an inorganic glass layer and a silicon oxide polymer layer has been proposed (see, for example, Patent Document 1). According to Patent Document 1, such a laminate substrate is said to be excellent in gas barrier properties, flexibility, heat resistance and transparency. However, the laminate substrate of Patent Document 1 is still insufficient in thermal expansion, and the secondary workability and operability are insufficient.

 Patent Document 1: Japanese Patent Application Laid-Open No. 2004-50565

 Disclosure of the invention

 Problems to be solved by the invention

[0007] The present invention has been made to solve the above-described conventional problems, and the object thereof is excellent in gas barrier properties, flexibility, heat resistance, and transparency, and dimensional stability, operation. It is to provide a substrate for a display element that is excellent in performance and secondary workability and a simple manufacturing method thereof.

 Means for solving the problem

The display element substrate of the present invention includes an inorganic glass and a resin layer disposed on both sides of the inorganic glass.

 In a preferred embodiment, the total thickness d of the resin layer and the thickness of the inorganic glass

 rsum

 The ratio d / ά to d is 0 · 5 to 2 · 2.

 g rsum g

 In a preferred embodiment, the resin layers on both sides of the inorganic glass are made of the same material, have the same thickness, and the thickness of each resin layer is the inorganic glass. Is equal to the thickness of

 In a preferred embodiment, the total thickness of the display element substrate is 150 111 or less.

In a preferred embodiment, an average linear expansion coefficient at 170 ° C. of the display element substrate is 20 ppm ° C. ¹ or less. In a preferred embodiment, the display element The fracture diameter when the substrate is curved is 30 mm or less. In a preferred embodiment, the transmittance of the display element substrate is 85% or more.

In a preferred embodiment, the thickness d of the inorganic glass is 1 μ 111 to 50 m.

 g

 In a preferred embodiment, the resin layer is formed from a resin composition containing an epoxy resin as a main component.

[0015] In a preferred embodiment, the Young's modulus at 25 ° C of the resin layer is 1 GPa or more.

 In a preferred embodiment, the resin layer is provided directly on the inorganic glass.

 [0017] According to another aspect of the present invention, a method of manufacturing a display element substrate is provided. This production method includes bonding a semi-cured resin composition to inorganic glass and completely curing the resin composition bonded to the inorganic glass.

 The invention's effect

 [0018] According to the present invention, there is provided a display element substrate having resin layers on both sides of an inorganic glass. In such a substrate, since the inorganic glass disposed in the center functions as a gas barrier layer, it is possible to contribute to the thinning of the substrate without the need for additionally laminating the gas barrier layer. In addition, the inorganic glass placed in the center part suppresses the thermal expansion of the resin layer that should have a high linear expansion coefficient, and a laminate having a small linear expansion coefficient can be obtained. Therefore, the display element substrate of the present invention is particularly effective as a TFT substrate requiring a high temperature process. Furthermore, the breakage of the inorganic glass plate is generally caused by stress concentration on the surface micro-defects, and the thinner the thickness, the more likely the breakage occurs. On the other hand, in the display element substrate of the present embodiment, since the resin layers arranged on both sides relieve stress in the tearing direction to defects during deformation, even when the inorganic glass is thinned, Breaking is unlikely to occur, making it possible to further reduce the thickness and weight. The fact that such an effect can be obtained by laminating the resin layers on both surfaces of the inorganic glass is a finding first found by the present inventors, and is an unexpectedly excellent effect.

Brief Description of Drawings FIG. 1 (a) is a schematic sectional view of a display element substrate according to one embodiment of the present invention, and (b) is a schematic view of a display element substrate according to another embodiment of the present invention. It is sectional drawing.

 Explanation of symbols

[0020] 10 Inorganic glass

 11, 11 'resin layer

 12, 12 'adhesive layer

 100 Display element substrate

 BEST MODE FOR CARRYING OUT THE INVENTION

 [0021] A. Overall structure of the display device plate

 FIG. 1 (a) is a schematic cross-sectional view of a display element substrate according to a preferred embodiment of the present invention. The display element substrate 100 includes an inorganic glass 10 and resin layers 11 and 1 Γ arranged on both sides of the inorganic glass 10. By having such a configuration, a display element substrate having excellent gas barrier properties, flexibility, heat resistance, and transparency, and excellent dimensional stability, operability, and secondary workability can be obtained. More preferably, the resin layers 11 and ΓΓ on both sides are made of the same material and have the same thickness (that is, the display element substrate has a so-called symmetrical arrangement). By having such a structure, it is possible to obtain a substrate having a small linear expansion coefficient and an extremely excellent operability and secondary workability.

 Preferably, as shown in FIG. 1 (a), the respective resin layers 11 and 1 Γ are provided directly on the inorganic glass 10 (that is, without an adhesive layer). By having such a configuration, a thinner substrate can be realized. The display element substrate having such a configuration can be manufactured by a manufacturing method described later. If necessary, as shown in FIG. 1 (b), the respective resin layers 11, 1 Γ may be fixed to the glass substrate via the adhesive layers 12, 12 ′. The adhesive layer is composed of any appropriate adhesive or pressure-sensitive adhesive.

 [0023] The ratio d / d between the total thickness d of the resin layer and the thickness d of the inorganic glass is preferable.

 rsum g rsum g

It is 0.5 to 2.2, more preferably 1.5 to 2.1, and particularly preferably about 2. When the total thickness of the resin layer and the thickness of the inorganic glass have such a relationship, warpage and undulation of the substrate in the heat treatment can be satisfactorily suppressed. Particularly preferably, the substrate is paired. The difference (d−d) between the thickness d of each resin layer and the thickness d of the inorganic glass is preferably −45 111 to 20 111, more preferably 35 m or more; 10〃m, most preferably d is equal to d. By adopting such a configuration, even when the display element substrate is subjected to heat treatment, thermal stress is evenly applied to both surfaces of the inorganic glass, so that warpage and undulation are extremely unlikely to occur. In this specification, “equal” includes not only strictly equal but also substantially equal.

 [0024] The total thickness of the display element substrate is preferably 150 in or less, more preferably 5 0 111 to 100 111. According to the present invention, by adopting the above-described configuration, the thickness of the inorganic glass can be made much thinner than that of a conventional glass substrate. As a result, a light-weight and thin display element substrate having excellent flexibility can be obtained.

[0025] The average linear expansion coefficient at 170 ° C of the display element substrate is preferably 20 ppm ° C-1 or less, and more preferably lOpprnt ¹ or less. Within the above range, for example, when used in a liquid crystal display element, even when subjected to a plurality of heat treatment steps, pixel displacement and wiring breakage / cracking are unlikely to occur.

 [0026] The fracture diameter when the display element substrate is bent is preferably 30 mm or less, and more preferably 10 mm or less.

 [0027] The transmittance of the display element substrate at a wavelength of 550 nm is preferably 85% or more, and more preferably 90% or more. Preferably, the display element substrate has a light transmittance reduction rate of 5% or less after heat treatment at 180 ° C. for 2 hours. This is because, with such a reduction rate, a practically acceptable light transmittance can be ensured even if a necessary heat treatment is performed in the manufacturing process of the liquid crystal display element. One of the effects of the present invention is that these characteristics are realized while employing the resin layer.

 [0028] The surface roughness Ra of the display element substrate (substantially, the surface roughness Ra of the resin layer of the substrate) is preferably 50 nm or less, and more preferably 30 nm or less. The waviness of the display element substrate is preferably 0.5 m or less, and more preferably 0 l ^ m or less. A display element substrate having such characteristics is excellent in quality. Such characteristics can be realized by, for example, a manufacturing method described later.

[0029] The in-plane retardation Re (550) of the display element substrate at a wavelength of 550 nm is preferably It is 10 nm or less, more preferably 5 nm or less. The retardation Rth (550) in the thickness direction at a wavelength of 550 nm of the display element substrate is preferably 20 nm or less, more preferably 10 nm or less. If the optical characteristics are within the above ranges, for example, even when the substrate is used in a liquid crystal display device, the display characteristics are not adversely affected. One of the effects of the present invention is that such characteristics are realized while employing the resin layer. The in-plane retardation Re (λ) and the thickness direction retardation Rth (λ) at the wavelength λ can be obtained from the following equations, respectively. In the equation, ηχ is the refractive index in the slow axis direction, ny is the refractive index in the fast axis direction, nz is the refractive index in the thickness direction, and d is the thickness. The slow axis refers to the direction in which the refractive index becomes maximum in the plane, and the fast axis refers to the direction orthogonal to the slow axis in the plane.

Yes

 Re (λ) = (nx-ny) X d

 Rth (l) = (nx-nz) X d

[0030] B. Inorganic glass

 As the inorganic glass used for the display element substrate of the present invention, any appropriate one can be adopted as long as it is plate-shaped. Examples of the inorganic glass include soda lime glass, borate glass, aluminosilicate glass, and quartz glass according to the classification according to the composition. Further, according to the classification based on the alkali component, alkali-free glass and low-alkali glass can be mentioned. The content of alkali metal components (eg Na 0, K 0, Li Ο) in the inorganic glass is

 2 2 2

 The amount is preferably 15% by weight or less, more preferably 10% by weight or less.

[0031] The inorganic glass preferably has a thickness of 1 m to 100 m, more preferably 10 m.

 a m to 70 am, and particularly preferably 25 m to 55 μm. In the present invention, the force S can be used to reduce the thickness of the inorganic glass by arranging the resin layers on both sides of the inorganic glass.

 [0032] The transmittance of the inorganic glass at a wavelength of 550 nm is preferably 90% or more. The refractive index n of the inorganic glass at a wavelength of 550 nm is preferably from 1.4 to;

 g

[0033] The average thermal expansion coefficient of the inorganic glass is preferably lOppmOC i O. Spprnt ¹ , more preferably SppmOC i O. Spprnt ¹ . If it is the inorganic glass of the said range, the dimensional change of a resin layer can be suppressed effectively in a high temperature or low temperature environment. [0034] The density of the inorganic glass is preferably ^2.3 g / cm ³ to 3. Og / cm ^3, and more preferably ^2.3 g / cm ³ to 2.7 g / cm ³ . If it is the inorganic glass of the said range, a lightweight substrate for display elements will be obtained.

 [0035] Any appropriate method may be adopted as the method of forming the inorganic glass. Typically, the inorganic glass is a mixture of a main raw material such as silica and alumina, an antifoaming agent such as antimony oxide and a reducing agent such as carbon, and a mixture of 1400 ° C to 1600 ° C. It is made by melting at temperature, forming into a thin plate, and then cooling. Examples of the method for forming the inorganic glass sheet include a slot down draw method, a fusion method, and a float method. The inorganic glass formed into a plate shape by these methods may be chemically polished with a solvent such as hydrofluoric acid, if necessary, in order to reduce the thickness or improve the smoothness.

 [0036] As the inorganic glass, a commercially available glass may be used as it is, or a commercially available inorganic glass may be polished to have a desired thickness. Examples of commercially available inorganic glasses include “7059”, “1737” or “EAGLE 2000” manufactured by Coung, “AN100” manufactured by Asahi Glass, “NA-35” manufactured by NH Techno Glass, and “NA-35” manufactured by Nippon Electric Glass Co., Ltd. OA-10 ”

[0037] c m m

 The resin layer used for the display element substrate of the present invention is disposed on both surfaces of the inorganic glass. The thickness d of the resin layer is preferably l ^ m to 100 ^ m, more preferably l〃m to 50111. The thickness of each resin layer may be the same or different. Preferably, as described above, the thickness of each resin layer is the same. Further, each resin layer may be made of the same material or different materials. Preferably, each resin layer is made of the same material. Therefore, most preferably, each resin layer is made of the same material and the same thickness. The total thickness d of the resin layer is preferably 2 H m to 200 μm, more preferably 2 μm.

 rsum

 m to 100 μm.

 [0038] The transmittance of the resin layer at a wavelength of 550 nm is preferably 85% or more. The refractive index (n) of the resin layer at a wavelength of 550 nm is preferably 1.3 to 1.7. The difference between the refractive index (n) of the resin layer and the refractive index (n) of the inorganic glass is preferably 0.2 or less.

Γ g More preferably 0.1 or less. If it is such a range, the bad influence on the display characteristic resulting from the refractive index difference of inorganic glass and a resin layer can be prevented.

 [0039] The elastic modulus (Young's modulus) of the resin layer is preferably 1 GPa or more, and more preferably 1.5 GPa or more. By setting it as the above range, even when the inorganic glass is thinned, the resin layer relaxes the stress in the tearing direction to the defects at the time of deformation.

 [0040] As a material constituting the resin layer, any appropriate resin (substantially a resin composition containing the resin as a main component: hereinafter, the resin and the resin composition are collectively referred to as "resin". Force S) may be employed. A resin excellent in heat resistance is preferred. More preferably, the resin is a thermosetting or ultraviolet curable resin. Examples of such resins include polyethersulfone resins, polycarbonate resins, epoxy resins, acrylic resins, and polyolefin resins. Particularly preferably, the resin layer is formed of a resin composition containing an epoxy resin as a main component. This is because a resin layer having excellent surface smoothness and good hue can be obtained.

 [0041] The epoxy resin may be any appropriate one as long as it has an epoxy group in the molecule. Examples of the epoxy resin include bisphenol A type, bisphenol F type, bisphenol S type, and bisphenol types such as water additives thereof; nopolac types such as phenol nopolac type and cresol nopolac type; Nitrogen-containing ring type such as triglycidyl isocyanurate type hydantoin type; alicyclic type; aliphatic type; aromatic type such as naphthalene type, biphenyl type; glycidyl ether type, glycidylamine type, glycidyl ester Examples thereof include glycidyl type such as mold; dicyclo type such as dicyclopentagen type; ester type; ether ester type; and modified types thereof. These epoxy resins can be used alone or in admixture of two or more.

[0042] Preferably, the epoxy resin is a bisphenol A type epoxy resin, an alicyclic type epoxy resin, a nitrogen-containing ring type epoxy resin, or a glycidyl type epoxy resin. When the epoxy resin is a nitrogen-containing ring type, it is preferably a triglycidyl isocyanurate type epoxy resin. These epoxy resins are excellent in discoloration prevention. [0043] Preferably, the resin layer is a cured layer of at least one epoxy prepolymer selected from the group consisting of the following general formulas (1), (11), (III) and (IV).

[0044] [Chemical 1]

[0045] In the above formula (I), X and X are each independently a covalent bond, a CH group, a C (CH) group,

 3 2

C (CF) group, CO group, oxygen atom, nitrogen atom, SO group, Si (CH CH) group, or N (CH

 3 2 3 2

) Represents a group. Y to Y are substituents, and a to d represent the number of substitutions. Y ~ Y it

3 1 4 1 4 Independently, a hydrogen atom, a halogen atom, an alkyl group having 1 to 4 carbon atoms, a substituted alkyl group having 1 to 4 carbon atoms, a nitro group, a cyano group, a thioalkyl group, an alkoxy group, an aryl group Represents a substituted aryl group, an alkyl ester group, or a substituted alkyl ester group. a to d are integers from 0 to 4, and 1 is an integer of 2 or more.

 [0046] [Chemical 2]

In the above formula (II), X and X are each independently a CH group, a C (CH 3) group, or a C (CF 3) group.

 3 4 2 3 2 3 2 represents a group, CO group, oxygen atom, nitrogen atom, SO group, Si (CH CH) group, or N (CH) group

 2 2 3 2 3 Y to Y are substituents, and e to g represent the number of substitutions. Y to Y are independent

5 7 5 7

A hydrogen atom, a halogen atom, an alkyl group having 1 to 4 carbon atoms, a carbon atom; a substituted alkyl group having 4 to 4 carbon atoms, a nitro group, a cyano group, a thioalkyl group, an alkoxy group, an aryl group, a substituted aryl group, Represents an alkyl ester group or a substituted alkyl ester group. e and g are 0 to 4 , F is an integer from 0 to 3, m is an integer greater than or equal to 2,

[0048] [Chemical 3]

In the above formula (III), X to X each independently represent a covalent bond, a CH group, a C (CH 3) group,

 5 7 2 3 2

C (CF) group, CO group, oxygen atom, nitrogen atom, SO group, Si (CH CH) group, or N (CH

 3 2 2 2 3 2

) Represents a group. Y is any one of the above formulas (a) to (d).

 3 8

 [0050] [Chemical 4]

[0051] In the above formula (IV), n and m are respectively; Represents an integer of ~ 6. Y is

9 This is a moiety represented by the above formula (a) or (b). [0052] The epoxy equivalent (mass per epoxy group) of the epoxy resin is preferably 100 g / eqiv. To 1000 g / eqiv. If it is the said range, the softness | flexibility and intensity | strength of the resin layer which can be obtained can be improved.

 [0053] The softening point of the epoxy resin is preferably 120 degrees or less. The epoxy resin is preferably a liquid at normal temperature (for example, 5 to 35 ° C.). More preferably, the epoxy resin is a two-component mixed epoxy resin that is liquid at or below the coating temperature (particularly at room temperature). It is because it is excellent in developability and coating property when forming the resin layer.

 [0054] The resin composition may further contain any appropriate additive depending on the purpose. Examples of the additives include curing agents, curing accelerators, diluents, anti-aging agents, denaturing agents, surfactants, dyes, pigments, anti-discoloring agents, ultraviolet absorbers, softeners, stabilizers, plasticizers, An antifoaming agent etc. are mentioned. The type, number and amount of additives contained in the resin composition can be appropriately set depending on the purpose.

 [0055] As the resin composition, a commercially available product may be used as it is, or an optional additive and / or resin may be added to a commercially available product. Examples of commercially available epoxy resins (resin compositions) include Grade 827 and Grade 828 manufactured by Japan Epoxy Resin, and EP Series and KR Series manufactured by Ade Power Company.

 [0056] 1¾ method of D. ^

 The method for producing a display element substrate of the present invention includes bonding a semi-cured resin composition to inorganic glass and completely curing the resin composition bonded to the inorganic glass. According to such a manufacturing method, it is possible to directly fix the resin layer through the adhesive layer to the inorganic glass.

[0057] In one embodiment, the method for producing a display element substrate of the present invention comprises applying a resin composition on a release film and semi-curing the resin composition to form a semi-cured layer. Bonding the semi-cured layer to the inorganic glass, coating the resin composition on the side where the semi-cured layer of the inorganic glass is not bonded, and the semi-cured layer and the coated resin composition Is completely cured to form a resin layer on both sides of the inorganic glass. In another embodiment, the method for producing a display element substrate of the present invention comprises preparing two laminates of a release film / semi-cured layer, and forming the semi-cured layer of each laminate with an inorganic glass. Bonding to each side of the glass and completely curing the semi-cured layers on both sides of the inorganic glass to form a resin layer.

[0058] The resin composition is as described in Section C.

 [0059] Coating methods for the resin composition include air doctor coating, blade coating, knife coating, reverse coating, transfer roll coating, gravure roll coating, kiss coating, cast coating, spray coating, and slot orifice. Coating methods such as coating, calendar coating, electrodeposition coating, date coating, and die coating; relief printing methods such as flexographic printing, intaglio printing methods such as direct gravure printing methods and offset gravure printing methods, and lithographic plates such as offset printing methods Examples of the printing method include a printing method such as a stencil printing method such as a screen printing method.

 [0060] During coating, leveling agents such as silicone oil and additives such as curing agents may be added to the resin composition as necessary to apply the coating liquid and ink. The power to improve Furthermore, by applying a silane treatment to the surface of the inorganic glass or by mixing a silane coupling agent with the resin composition, the inorganic glass and the coating resin composition (final resin layer) are adhered to each other. Can increase the sex.

[0061] A typical example of the silane coupling agent is aminosilane. Specific examples of aminosilanes include γ-aminopropyltriethoxysilane, _Ί- aminopropyltrimethoxysilane, Ν-β ~ (aminoethyl) γ-aminopropyltrimethoxysilane, γ-ureidopropyltriethoxysilane. Γ-Ν phenylaminopropyltrimethoxysilane. These aminosilanes can be used alone or in combination of two or more. In addition, a coupling agent other than aminosilane may be used in combination.

 [0062] The laminate (release film / semi-cured layer) and the inorganic glass are bonded to each other by any appropriate means. Typically, laminating is performed. For example, when laminating a laminate on both sides of an inorganic glass, a substrate for a display element can be manufactured with extremely excellent production efficiency by continuously supplying and laminating a roll-like laminate to inorganic glass. can do.

[0063] The curing method of the resin composition may be appropriately selected depending on the type of epoxy resin contained in the resin composition. If the epoxy resin is thermosetting, The composition is semi-cured and fully cured by heating. The heating conditions can be appropriately selected according to the type of epoxy resin, the composition of the resin composition, and the like. In one embodiment, the heating conditions for semi-curing the coated resin composition are a temperature of 100 ° C. to 150 ° C. and a heating time of 5 minutes to 30 minutes. In one embodiment, the heating conditions for fully curing the semi-cured layer are a temperature of 170 ° C. to 200 ° C. and a heating time of 60 minutes or more. When the epoxy resin is an ultraviolet curable resin, the resin composition is semi-cured and completely cured by ultraviolet irradiation. Irradiation conditions can be appropriately selected according to the type of epoxy resin, the composition of the resin composition, and the like. In one embodiment, the irradiation conditions for semi-curing the coated resin composition are an irradiation intensity of 40 mW / cm ^{2 to} 60 mW / cm ² and an irradiation time of 3 seconds to 15 seconds. In one embodiment, the irradiation conditions for completely curing the semi-cured layer are an irradiation intensity of 40 mW / cm ^{2 to} 60 mW / cm ² and an irradiation time of 5 minutes to 30 minutes. If necessary, a heat treatment may be performed after the ultraviolet irradiation for completely curing the semi-cured layer. The heat treatment conditions in this case are, for example, a temperature of 130 ° C. to 150 ° C. and a heating time of 10 minutes to 60 minutes.

 In the above description, the embodiment in which the semi-cured resin composition is attached to the inorganic glass has been described. However, in the present invention, the completely cured resin composition (resin layer) is added to the inorganic glass. It goes without saying that it may be attached. In this case, any appropriate adhesive layer can be used as required.

 [0065] For j.

 The display element substrate of the present invention can be used for any appropriate display element. Examples of the display element include a liquid crystal display, a plasma display, and an organic EL display. Among these, the display element substrate of the present invention is suitable for a liquid crystal display.

[0066] When used in a liquid crystal display, the display element substrate of the present invention uses all the processes applied to a conventional glass substrate as it is, and uses a segment method, a simple matrix method, an active matrix method using TFT, or the like. It can be applied to electrode formation corresponding to all drive systems, and can be used for both transmissive and reflective display systems. These display devices include display devices for small-sized portable information terminal devices, word processors, personal computers. Information equipment such as computers and workstations, business equipment, and display devices such as large panels are incorporated into these devices.

Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited to these examples. The evaluation method of the display element substrate of the example is shown below.

(1) thickness;

 Measurement was performed using an Anritsu digital micrometer “KC-351C type”.

(2) Average coefficient of linear expansion;

 TMA / S S 150C (manufactured by Seiko Instruments Inc.) was used to measure 30 to 30 ° C; TMA value at 170 ° C m), and an average linear expansion coefficient was calculated.

 (3) Light transmittance;

 The transmittance at a wavelength of 550 nm was measured using a high-speed spectrophotometer (CMS-500, manufactured by Murakami Color Research Laboratory, using a halogen lamp).

 (4) Breaking diameter;

 A substrate (size: lOmm x 50mm, number of samples: 5) is wound around cylinders with different diameters, and the breakage of the inorganic glass is visually confirmed. The average of the diameters of the cylinders for the five samples where breakage is confirmed is the break diameter. did.

 (5) Young's modulus;

 A measurement sample (25 mm x 50 mm) was cut out from a 50 mm thick resin film and calculated from a stress-strain curve when a tensile load was applied to the measurement sample up to 20 N using an autograph (manufactured by Shimadzu Corporation).

 (6) In-plane retardation and thickness direction retardation;

 Measurement was performed at 23 ° C. and a wavelength of 550 nm using a trade name “AxoScan” manufactured by Axometrics. As the average refractive index, a value measured using an Abbe refractometer [product name “DR-M4” manufactured by Atago Co., Ltd.] was used.

[0068] (Example)

A resin composition mainly composed of an epoxy resin ((1): (2) = 50:50 (weight ratio)) represented by the following chemical formula is sandwiched between release films subjected to silicone treatment, and δθ Included an epoxy resin layer with a thickness of 30 m through a metal roll fixed at πι A laminate was obtained. Next, using an ultraviolet irradiation device (conveyor speed: 2.5 m / min), ultraviolet light was irradiated from one side of the laminate (irradiation energy: 250 mj / cm ² ), and the epoxy resin layer was half-coated. Cured to form a semi-cured layer. Next, one release film is removed, and a semi-cured layer of the above laminate is attached to the surface of one side of inorganic glass (Matsunami Glass Borosilicate Glass, thickness: 30 m) using a laminator. did. The same operation was performed on the other side of the inorganic glass, and a semi-cured layer was adhered. Next, the remaining peeled film was removed and then irradiated again with ultraviolet rays (irradiation energy: 5000 mj / cm ² or more). After that, heat treatment (over 130 ° C, over 10 minutes) was applied to completely cure the semi-cured layers on both sides of the inorganic glass. In this way, a display element substrate having a structure of resin layer (30 11 m) / inorganic glass (30 11 m) / resin layer (3 O ^ m) was obtained.

[0069] [Chemical 5]

[0070] The following table shows the linear expansion coefficient, transmittance, bending resistance, and Young's modulus of the resin layer of the obtained display element substrate.

[0071] [Table 1] Thickness (μ πι) Approx. 9 0

Average linear expansion coefficient (pp rntT ¹ ) 1 0

 Light transmittance (%) 9 0

 Breaking diameter (mm) 2 0

 Young's modulus (G P a) 2.5

 In-plane phase difference (n m) 0.5

Thickness direction retardation (nm) 2 0 The display element substrate of the present invention can be widely used in display elements such as liquid crystal displays, plasma displays, and organic EL displays. In particular, it can be suitably used for a liquid crystal display.

Claims

The scope of the claims  [I] A display element substrate comprising inorganic glass and a resin layer disposed on both sides of the inorganic glass.  [2] The ratio d / d between the total thickness d of the resin layer and the thickness d of the inorganic glass is 0.5 · 2  rsum g rsum g  The display element substrate according to claim 1, wherein the display element substrate is 2. [3] The resin layers on both sides of the inorganic glass are made of the same material, have the same thickness, and the thickness of each of the resin layers is equal to the thickness of the inorganic glass. The display element substrate according to 1 or 2. [4] The display element substrate according to any one of claims 1 to 3, wherein a total thickness of the display element substrate is 150 ^ 111 or less. 5. The display element substrate according to any one of claims 1 to 4, wherein an average linear expansion coefficient at 170 ° C of the display element substrate is 20 ppm ° C ¹ or less. 6. The display element substrate according to any one of claims 1 and 5, wherein a fracture diameter when the display element substrate is curved is 30 mm or less. 7. The display element substrate according to any one of claims 1 to 6, wherein the transmittance of the display element substrate is 85% or more. [8] The inorganic glass according to any one of claims 1 to 7, wherein the inorganic glass has a thickness d force of μm to 50 μm.  g  Display device substrate.  [9] The display element substrate according to any one of [1] to [8], wherein the resin layer is formed from a resin composition containing an epoxy resin as a main component. [10] The display element substrate according to any one of claims 1 to 9, wherein the resin layer has a Young's modulus at 25 ° C of lGPa or more.  [I I] The display element substrate according to any one of claims 1 to 10, wherein the resin layer is directly provided on the inorganic glass.  [12] A method for producing a substrate for a display element, comprising: bonding a semi-cured resin composition to inorganic glass; and completely curing the resin composition bonded to the inorganic glass.